A far-infrared heating plate and a preparation method thereof

Abstract

The present invention discloses a far-infrared heating plate and a preparation method thereof, belonging to the field of heating accessories, which solves the problem of power reduction of the graphene heating plate due to oxidation. The solution includes that, from bottom to top in the thickness direction, it is composed of a base layer, an electrode layer, a heating layer, an adhesive layer and a cover glass, and pre-oxidation is carried out through secondary curing. After the graphene high-temperature slurry is cured once and then heat-treated at high temperature again, it can not only reduce the residual organic matters in the system, but also enable the carbon material to be pre-oxidized one step ahead after the secondary heat treatment, avoiding the power drop caused by oxidation during subsequent use.

Description

Technical Field

[0001] The present invention relates to the field of heating, and particularly to a far-infrared heating plate and a preparation method thereof. Background Art

[0002] Graphene is an allotrope of carbon, and carbon atoms are bonded by sp 2 hybridization to form a single-layer hexagonal honeycomb lattice graphene. Using this crystal structure of graphene, fullerenes (C60), graphene quantum dots, carbon nanotubes, nanoribbons, multi-walled carbon nanotubes, and nanohorns can be constructed. Stacked graphene layers (more than 10 layers) form graphite, and the layers are held together by van der Waals forces, with an interplanar spacing of 0.335 nanometers. Graphene has excellent optical, electrical, and mechanical properties and has important application prospects in materials science, micro-nano processing, energy, biomedicine, and drug delivery, etc., and is considered a revolutionary material for the future.

[0003] Heaters come in various shapes. The heating plate converts electrical energy into heat energy. According to different conversion methods of electrical energy, electric heating is usually divided into resistance heating, induction heating, arc heating, electron beam heating, infrared heating, and dielectric heating, etc. Since infrared rays have strong penetration ability, are easily absorbed by objects, and once absorbed by an object, they immediately turn into heat energy; the energy loss before and after infrared heating is small, the temperature is easy to control, and the heating quality is high. Therefore, the application of infrared heating has developed rapidly.

[0004] Currently, hot air ovens or resistance heating plates commonly used in laboratories. After the graphene slurry in the graphene heating plate is cured, organic residues are likely to be generated inside. At the same time, when the graphene heating plate is in use, the heating power of the heating plate decreases due to the oxidation of the graphene material. Summary of the Invention

[0005] The purpose of the present invention is to provide a far-infrared heating plate and a preparation method thereof, which have the functions of eliminating residual organic matter and avoiding power reduction by pre-oxidizing the carbon material.

[0006] The above technical purpose of the present invention is achieved through the following technical solutions: A far-infrared heating plate, which from bottom to top in the thickness direction is composed of a base layer, an electrode layer, a heating layer, a bonding layer, and a cover glass. The base layer includes microcrystalline ceramics or microcrystalline glass. The electrode layer is formed by printing or coating aluminum foil or copper foil or nickel foil or gold foil or silver foil or aluminum conductive paste or copper conductive paste or nickel conductive paste or gold conductive paste or silver conductive paste. The heating layer is formed by printing graphene high-temperature slurry and curing once at 200 - 300 °C. The bonding layer is formed by coating glass paste. After being formed by curing once, the base layer, the electrode layer, the heating layer, the bonding layer, and the cover glass are cured a second time at 450 - 600 °C.

[0007] Preferably, the graphene high-temperature slurry is composed of the following raw materials by mass percentage, including 20 parts - 35 parts of conductive carbon materials, 15 parts - 30 parts of inorganic fillers, 15 parts to 65 parts of inorganic resins, and 5 parts to 10 parts of additives.

[0008] Preferably, the thickness of the electrode layer is 5μm or 10μm or 20μm or 30μm; the distance between two parallel electrode layers is 10 - 30 cm.

[0009] Preferably, the thickness of the base layer is 3000 - 5000μm, the thickness of the heating layer is 30 - 60μm, the thickness of the bonding layer is 30 - 80μm, and the thickness of the cover glass is 2000 - 3000μm.

[0010] By adopting the above technical solution, the thickness of the bonding layer should be greater than or equal to the thickness of the heating layer, otherwise moisture will enter through the gap and affect the power.

[0011] Preferably, it is used for an infrared drying oven.

[0012] Another object of the present invention is to provide a preparation method of a far-infrared heating plate.

[0013] Another object of the present invention is achieved through the following technical solution: a preparation method of a far-infrared heating plate, including the following steps,

[0014] Step 1: Print a high-temperature resistant conductive material on the substrate to form an electrode layer;

[0015] Step 2: Print the graphene high-temperature slurry on the microcrystalline glass layer and the electrode layer, and cure it in an environment with a temperature of 200 - 300°C to form a heating layer, and the curing time is 10 - 20 minutes;

[0016] Step 3: Apply glue around the substrate to form a bonding layer;

[0017] Step 4: Cover the cover glass on the bonding layer, sinter and adhere, the sintering and curing temperature is 450 - 600°C, and the sintering and curing time is 10 - 30 minutes.

[0018] Preferably, the bonding layer is made of glass slurry, and the glass slurry includes glass powder and solvent.

[0019] By adopting the above technical solution, it has the same or similar light transmittance as the glass cover plate, ensuring the projection effect of infrared rays.

[0020] Preferably, the bonding layer is arranged around the heating layer, the width of the bonding layer is 500μm - 2000μm, and a sintering gap is formed between the top of the heating layer and the bottom of the cover glass.

[0021] By adopting the above technical solution, through secondary heat treatment between the heating layer and the cover plate, and then through the melting of the bonding layer, the cover plate and the heating layer are pressed tightly, reducing the theoretical sintering gap between the two.

[0022] To sum up, the graphene high-temperature slurry is heat-treated at high temperature again after primary curing, which can not only reduce the residual organic matter in the system, but also pre-oxidize the carbon material after secondary heat treatment, avoiding the power drop caused by oxidation during subsequent use. At the same time, the addition of the bonding layer and the cover plate glass can also prevent moisture intrusion. Description of the Drawings

[0023] Figure 1 is the top view of the embodiment after removing the cover plate glass;

[0024] Figure 2 is the side cross-sectional view of the embodiment;

[0025] In the figure, 1, base layer; 2, electrode layer; 3, heating layer; 4, bonding layer; 5, glass cover plate. Detailed Embodiment

[0026] The present invention will be further described in detail below with reference to the accompanying drawings.

[0027] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0028] Embodiment:

[0029] As Figure 1 and Figure 2 shown, a far-infrared heating plate has the following structure. This kind of far-infrared heating plate can be used in an infrared drying oven. From bottom to top in the thickness direction, it is composed of a base layer 1, an electrode layer 2, a heating layer 3, a bonding layer 4 and a cover plate glass. Among them, the bonding layer 4 is outside the electrode layer 2 and the heating layer 3 before heat treatment, and plays the role of bonding the outside of the electrode layer 2 and the heating layer 3 after heat treatment. The base layer 1 includes microcrystalline ceramics or microcrystalline glass. The electrode layer 2 is formed by printing or coating aluminum foil or copper foil or nickel foil or gold foil or silver foil or aluminum conductive paste or copper conductive paste or nickel conductive paste or gold conductive paste or silver conductive paste. One or more of the electrode layer 2 can be used in the following embodiments. The heating layer 3 is formed by printing graphene high-temperature slurry and curing it once at 200 - 300 °C. The bonding layer 4 is formed by coating glass paste. The base layer 1, the electrode layer 2, the heating layer 3, the bonding layer 4 and the cover plate glass are secondarily cured at 450 - 600 °C after primary curing.

[0030] Among them, the graphene high-temperature slurry is composed of raw materials in the following mass percentages, including 20 parts - 35 parts of conductive carbon materials, 15 parts - 30 parts of inorganic fillers, 15 parts to 65 parts of inorganic resins, and 5 parts to 10 parts of additives; meanwhile, the thickness of the electrode layer 2 is 5μm or 10μm or 20μm or 30μm, the distance between two parallel electrode layers 2 is 10 - 30 cm, the thickness of the base layer 1 is 3000 - 5000μm, the thickness of the bonding layer 4 is 30 - 80μm. Furthermore, theoretically, a sintering gap is formed between the top of the heating layer 3 and the bottom of the cover glass, the width of the bonding layer 4 is 500μm - 2000μm, and the thickness of the glass is 2000 - 3000μm.

[0031] This far-infrared heating plate is prepared by the following method.

[0032] A preparation method of a far-infrared heating plate includes the following steps.

[0033] Step 1: Print a high-temperature resistant conductive material on the substrate to form the electrode layer 2.

[0034] Step 2: Print the graphene high-temperature slurry on the microcrystalline glass layer and the electrode layer 2, and cure it in an environment with a temperature of 200 - 300°C to form the heating layer 3, and the curing time is 10 - 20 minutes.

[0035] Step 3: Apply glue around the substrate to form the bonding layer 4. The bonding layer 4 is made of glass paste, and the glass paste includes glass powder and solvent.

[0036] Step 4: Cover the cover glass on the bonding layer 4, sinter and adhere, the sintering and curing temperature is 450 - 600°C, and the sintering and curing time is 10 - 30 minutes.

[0037] The following table conducts two tests, namely:

[0038] Life test: Under the condition of sufficient heat release, the heating plate is energized at the rated voltage for 1 hour, powered off and cooled to room temperature for 0.5 hour (forced cooling is allowed), and the power change when the cumulative working time reaches 25000 hours is measured. If it is greater than 10%, it is unqualified.

[0039] Moisture resistance test: Put it into a damp heat box with a temperature of 40°C and a humidity of 88% for 480 hours, take it out and bake it in an oven at 60°C for 30 minutes, then restore it at normal temperature and humidity for 1 hour. After that, measure the test sample. It is required that the power change of the heating plate is less than 10% to be qualified. Table:

[0040]

Claims

1. A far-infrared heating plate, characterized in that: It is composed of a base layer (1), an electrode layer (2), a heating layer (3), an adhesive layer (4) and a cover glass from bottom to top in the thickness direction. The base layer (1) includes microcrystalline ceramics or glass-ceramics. The electrode layer (2) is formed by printing or coating aluminum foil, copper foil, nickel foil, gold foil, silver foil, aluminum conductive paste, copper conductive paste, nickel conductive paste, gold conductive paste or silver conductive paste. The heating layer (3) is formed by printing graphene high-temperature paste and curing it once at 200 - 300 °C. The adhesive layer (4) is formed by coating glass paste. Glue is applied around the substrate to form the adhesive layer (4), and the adhesive layer (4) is arranged around the heating layer (3). After being formed by one-time curing, the base layer (1), the electrode layer (2), the heating layer (3), the adhesive layer (4) and the cover glass are secondarily cured at 450 - 600 °C.

2. The far-infrared heating plate according to claim 1, characterized in that: The graphene high-temperature paste is composed of raw materials with the following mass percentages, including 20 - 35 parts of conductive carbon materials, 15 - 30 parts of inorganic fillers, 15 to 65 parts of inorganic resins, and 5 to 10 parts of additives.

3. The far-infrared heating plate according to claim 1, characterized in that: The thickness of the electrode layer (2) is 5 μm, 10 μm, 20 μm or 30 μm; the distance between two parallel electrode layers (2) is 10 - 30 cm.

4. The far-infrared heating plate according to claim 1, characterized in that: The thickness of the base layer (1) is 3000 - 5000 μm, the thickness of the heating layer is 30 - 60 μm, the thickness of the adhesive layer (4) is 30 - 80 μm, and the thickness of the cover glass is 2000 - 3000 μm.

5. The far-infrared heating panel according to claim 1, wherein: For an infrared drying oven.

6. A preparation method of a far-infrared heating plate, characterized in that: Including the following steps, Step 1: Print a high-temperature resistant conductive material on the substrate to form the electrode layer (2); Step 2: Print graphene high-temperature paste on the microcrystalline glass layer and the electrode layer (2), and cure it in an environment with a temperature of 200 - 300 °C to form the heating layer (3), and the curing time is 10 - 20 minutes; Step 3: Apply glue around the substrate to form the adhesive layer (4); Step 4: Cover the cover glass on the adhesive layer (4), sinter and adhere, the sintering and curing temperature is 450 - 600 °C, and the sintering and curing time is 10 - 30 minutes.

7. The preparation method of a far-infrared heating plate according to claim 6, characterized in that: The adhesive layer (4) is made of glass paste, and the glass paste includes glass powder and a solvent.

8. The preparation method of a far-infrared heating plate according to claim 6, characterized in that: The width of the adhesive layer (4) is 500 μm - 2000 μm, and a sintering gap is formed between the top of the heating layer (3) and the bottom of the cover glass.

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